Want to run bigger tires on your 1999–2006 Silverado/Sierra 1500 at stock height? Here’s what fits.
Stock Tire Sizes:
- 17" wheels: 245/65R17 or 265/70R17
- 18" wheels: 265/65R18
- 20" wheels: 275/55R20
Maximum Tires at Stock Height:
17" Wheels:
- 265/70R17: Works fine, very close to factory size
- 285/65R17: Fits on most builds, possible rubbing at full lock (check wheel offset)
- 285/70R17: Rubs on full lock – needs minor trimming or 1" level
18" Wheels:
- 275/65R18: Works well with stock suspension
- 285/65R18: Fits on most builds, marginal at full lock
20" Wheels:
- 285/55R20: Stock size on some LTZ models
- 305/55R20: Close to stock-height limit – possible rubbing
Wheel Offset Matters:
The factory wheel offset on most GMT800 trucks is +31mm to +44mm. Running a wheel with less positive offset (more backspace) moves the tire inward, reducing clearance issues.
Free Upgrade: Level the Front
For the best fitment, a 2" leveling kit allows significantly larger tires:
Rough Country 1307 2" Leveling Kit – Opens up fitment to 285/65R18 or 285/70R17 without rubbing.
What size are you running at stock height on your GMT800 1500?